165 research outputs found
Wake-Based Locomotion Gait Design for Aerobat
Flying animals, such as bats, fly through their fluidic environment as they
create air jets and form wake structures downstream of their flight path. Bats,
in particular, dynamically morph their highly flexible and dexterous armwing to
manipulate their fluidic environment which is key to their agility and flight
efficiency. This paper presents the theoretical and numerical analysis of the
wake-structure-based gait design inspired by bat flight for flapping robots
using the notion of reduced-order models and unsteady aerodynamic model
incorporating Wagner function. The objective of this paper is to introduce the
notion of gait design for flapping robots by systematically searching the
design space in the context of optimization. The solution found using our gait
design framework was used to design and test a flapping robot
Aerobat, A Bioinspired Drone to Test High-DOF Actuation and Embodied Aerial Locomotion
This work presents an actuation framework for a bioinspired flapping drone
called Aerobat. This drone, capable of producing dynamically versatile wing
conformations, possesses 14 body joints and is tail-less. Therefore, in our
robot, unlike mainstream flapping wing designs that are open-loop stable and
have no pronounced morphing characteristics, the actuation, and closed-loop
feedback design can pose significant challenges. We propose a framework based
on integrating mechanical intelligence and control. In this design framework,
small adjustments led by several tiny low-power actuators called primers can
yield significant flight control roles owing to the robot's computational
structures. Since they are incredibly lightweight, the system can host the
primers in large numbers. In this work, we aim to show the feasibility of
joint's motion regulation in Aerobat's untethered flights
Feedback Control Design for MARLO, a 3D-Bipedal Robot.
This work develops feedback controllers for bipedal walking in 3D on level ground, both in simulation and experimentally. MARLO is a new robot that has been designed for the study of 3D-bipedal locomotion, with the aim of combining energy efficiency, speed, and robustness with respect to natural terrain variations in a single platform. The robot is highly underactuated, having six actuators and, in single support, 13 degrees of freedom. Its sagittal plane dynamics are designed to embody the spring loaded inverted pendulum (SLIP), which has been shown to provide a dynamic model of the body center of mass during steady running gaits in a wide diversity of terrestrial animals. A detailed dynamic model is used to optimize walking gaits with respect to the cost of mechanical transport (cmt), a dimensionless measure of energetic efficiency.
A feedback controller is designed that balances the robot during the quiet standing mode, and another feedback policy is developed such that the robot can take a transition step from quiet standing to walking. A feedback controller is designed that stabilizes steady-state 3D walking gaits, despite the high degree of underactuation of the robot. These controllers are combined through a state machine that handles switching among the three controllers controllers. In experiments on planarized (2D) and untethered (3D) versions of the robot with point feet and passive feet (prosthetic feet) walking over flat ground or on a ramp with a shallow slope, the adaptability of the designed controller to the environment (planar or untethered, flat ground or ramp), and to the morphology of the robot (point feet or passive feet), is demonstrated. In experiments on a planarized version of the robot with passive feet, the controller yielded stable walking after starting from quiet standing, autonomously and without any intervention from the operator. In experiments on an untethered (3D) version of the robot, the controller was able to balance the robot over flat ground or on a shallow ramp during the quiet standing mode. In addition, the controller yielded six-untethered ``human-like'' steps after starting from quiet standing, autonomously without any intervention from the operator.PhDMechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102339/1/aramez_1.pd
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